High power lasers and microwaves generate large quantities of low quality waste heat, creating difficult thermal management challenges. These challenges are compounded by the efforts to place these systems on both large and small aircraft. Traditional approaches to thermal management are not suitable for these platforms, as they require unacceptable weight and volume devoted to the thermal management system, and as they rapidly exhaust a platforms thermal capacity.
The publication is stated to describe a recent development of phase change-based thermal energy storage (TES) materials at the Air Force Research Laboratory. This paper is informed to focus on hydrous salt composites as a promising class of passive TES materials able to regenerate (re-solidify) mid-flight. It is stated that hydrous salts offer significantly higher volumetric and specific energy densities (up to ~0.3 MJ/kg, ~0.4 MJ/m^3) than state of the art paraffin TES materials, as well as higher thermal conductivity (~0.5-0.6 W/m/K). Despite these advantages, hydrous salts have typically not gained much interest due to problems with chemical segregation (changing solidification and melting behavior over large numbers of cycles), under-cooling, and material incompatibilities. The paper is noted to discuss recent progress towards solutions to these challenges, permitting high energy density regenerative TES materials.